1. Field of the Invention
One or more embodiments setting forth the ideas described throughout this disclosure pertain to the field of calibration of sensor electronics, for example simultaneous calibration of multiple motion capture sensors that produce motion capture data. More particularly, but not by way of limitation, one or more aspects of the disclosure enable more than one or large numbers of motion capture elements having a diverse array of physical formats to be simultaneously calibrated using an embodiment of the invention.
2. Description of the Related Art
Motion capture elements enable digital capture of motion, generally through use of accelerometers and gyroscopes for example. The use of motion capture elements for various activities is increasing as the size of the devices decreases and the price of available solutions decreases. Motion capture elements are commercially available in very small physical formats such as microelectromechanical (MEMS) format. These types of sensors are also lightweight and are available on small memory card formats or other mounting types.
Although the use of accelerometers and gyroscopes is increasing, the general accuracy of known motion capture sensors or elements is limited for a variety of reasons. One reason for the limited accuracy of accelerometers and gyroscopes is that there is a cost associated with calibrating each device. Many manufactures skip this step since the base accuracy is good enough for simple applications, such as a cell phones or game controllers that makes use of accelerometers wherein high accuracy is not really required for available applications. Another limitation of known motion capture sensors occurs as a result of the mounting process when the motion capture discrete components are coupled with a mounting element. For example, when coupling a chip-based sensor to a printed circuit board, the temperature changes inherent in the manufacturing process may rise considerably, which changes the characteristics of the sensor, requiring further calibration. In addition, the exact orientation of the chip with respect to the PCB varies during the manufacturing process. To summarize, motion capture data is generally not calibrated in known devices to provide high accuracy due to manufacturing techniques and extra costs involved with calibration.
In systems that actually calibrate a motion capture element, a single motion capture element is generally mounted on a moveable table and rotated at a known rate for example. The motion capture data from the motion capture element is analyzed and a calibration factor for each axis of rotation and optionally acceleration is thus determined. Some devices, such as mobile phones may include motion capture elements on relatively large PCB's that are generally not calibrated for highly accurate motion capture. This is due to the size of the PCB's that are relatively large and can only be calibrated one at a time with known calibration machines.
To provide highly accurate motion capture data for high volume electronics device, there is thus a need for a calibration system for simultaneous calibration of multiple motion capture elements.